GLP1R and type 2 diabetes mellitus: As shown in Figure 9A, the T2DM-MLE group exhibited significantly higher serum GLP-1 levels compared with the untreated T2DM group at both time points (6 weeks: 4.85 ± 0.18 vs. 3.55 ± 0.05 pg/mL; 12 weeks: 5.95 ± 0.09 vs. 3.69 ± 0.04 pg/mL; p < 0.001, respectively).